No radio transmissions from the aircraft were reported; therefore, it could not be determined if the pilot attempted to contact the Grande Prairie FSS after take-off. It is possible that the pilot felt that he did not have to call the FSS to open his flight plan, or he may have been flying too low to communicate along the route. Weather conditions were good when the pilot departed Spirit River, but deteriorated as the pilot proceeded along his route. In the vicinity of the front, with lower cloud and reduced visibility in fog and rain, and over a sparsely populated area at night, surface references and the natural horizon would have become obscured. The pilot would have been forced to fly using the aircraft's instruments; however, his instrument time was limited to the training environment, and he likely had never flown in cloud or in conditions where the horizon was not visible. The pilot likely found it difficult to fly the aircraft on instruments, became disoriented, and lost control of the aircraft. The aircraft entered into a spiral dive from which the pilot did not recover.Analysis No radio transmissions from the aircraft were reported; therefore, it could not be determined if the pilot attempted to contact the Grande Prairie FSS after take-off. It is possible that the pilot felt that he did not have to call the FSS to open his flight plan, or he may have been flying too low to communicate along the route. Weather conditions were good when the pilot departed Spirit River, but deteriorated as the pilot proceeded along his route. In the vicinity of the front, with lower cloud and reduced visibility in fog and rain, and over a sparsely populated area at night, surface references and the natural horizon would have become obscured. The pilot would have been forced to fly using the aircraft's instruments; however, his instrument time was limited to the training environment, and he likely had never flown in cloud or in conditions where the horizon was not visible. The pilot likely found it difficult to fly the aircraft on instruments, became disoriented, and lost control of the aircraft. The aircraft entered into a spiral dive from which the pilot did not recover. The weather briefing indicated that the weather was marginal for the intended flight. The pilot did not make radio contact with any FSS facility en route. The pilot attempted to continue visual flight in deteriorating weather conditions. The accident occurred at night, in a sparsely populated area, and in low visibility conditions. The pilot was licensed and qualified for the flight, but it is likely that he had not previously flown in conditions that required flying solely by reference to the aircraft instruments. It could not be determined why the ELT did not function properly at the time of impact.Findings The weather briefing indicated that the weather was marginal for the intended flight. The pilot did not make radio contact with any FSS facility en route. The pilot attempted to continue visual flight in deteriorating weather conditions. The accident occurred at night, in a sparsely populated area, and in low visibility conditions. The pilot was licensed and qualified for the flight, but it is likely that he had not previously flown in conditions that required flying solely by reference to the aircraft instruments. It could not be determined why the ELT did not function properly at the time of impact. The pilot continued flight into deteriorating weather conditions, probably became disoriented, and lost control of the aircraft. The aircraft entered a spiral dive from which the pilot did not recover.Causes and Contributing Factors The pilot continued flight into deteriorating weather conditions, probably became disoriented, and lost control of the aircraft. The aircraft entered a spiral dive from which the pilot did not recover.